The present invention is concerned with light duty bench mounted machines employed to drive a tool such as a saw blade, file, burnishing mandrel, etc., in reciprocation to operate on a relatively small table supported workpiece as, for example, in jewelry making.
The invention is specifically disclosed as applied to a jig-saw in which an extremely fine saw blade is employed to cut intricate edge formations in fine detail. Typically, the machine includes a work table upon which the workpiece is supported and the reciprocating saw blade passes through a hole in the table. The workpiece is manually guided to the blade.
Because the table is mounted on the same frame as is the reciprocatory drive mechanism which drives the saw, vibratory forces generated by the drive mechanism are transmitted to the work table. Even minor vibrations of the work table are highly undesirable in an environment where precise and finely detailed patterns are being cut on a manually guided work piece of precious metal. Because the operator must rely on a fixed relationship between the path of the saw blade and the surface of the table, it is not a simple matter to isolate the table from vibrations generated by the saw reciprocating mechanism.
Frequently it is necessary that the workpiece be cut with a beveled edge. Typically cutting of beveled edges with saws of the type the present invention is concerned is accomplished by mounting the table for tilting movement and locking it in place at the desired angle. Where the angle of the cut requires tilting of the table to any substantial extent from its normal horizontal position, the operator finds it difficult to accommodate to the unnatural position of the table.
Because the saw blades employed in making intricate finely detailed cuts must be of extremely small cross section, and regulation of blade tension and blade deflection induced by the feeding of the workpiece against the blade must be carefully regulated.
The present invention is directed to a reciprocatory saw in which vibrations induced by the reciprocatory drive are substantially eliminated by a counterbalancing technique and in which the reciprocatory drive and saw may be tilted as a unit relative to a stationary horizontal work table. A saw blade clamping system which accommodates simple and rapid blade replacement cooperates wih a blade tensioning adjustment which is operable with the blade clamped.